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Chong Hyun Yoon

Publications and source records attributed to Chong Hyun Yoon.

12 recordsLinked to original sources
PubMed2003

Congenital intrahepatic arterioportal and portosystemic venous fistulae with jejunal arteriovenous malformation depicted on multislice spiral CT.

We report a symptomatic infant with very rare congenital arterioportal and portosystemic venous fistulae in the liver. Multislice CT after partial transcatheter embolisation revealed not only the complicated vascular architecture of the lesion, but also an incidental jejunal arteriovenous malformation which explained the patient's melena. The patient underwent ligation of the hepatic artery and resection of the jejunal arteriovenous malformation. Postoperative multislice CT clearly demonstrated the success of the treatment.

Arteriovenous Fistula↗
PubMed2003

Intra-abdominal desmoplastic small round-cell tumour: multiphase CT findings in two children.

We report the multiphase CT findings of intra-abdominal desmoplastic small round-cell tumour (DSRCT) in two children. CT showed a huge heterogeneous intraperitoneal mass with or without direct invasion into solid organs such as liver or kidney, extensive intraperitoneal seeding, intratumoural calcification, ascites, and lymphadenopathy. DSRCT should be included in the differential diagnosis of malignant intraperitoneal neoplasm in children. Multiphase CT may be helpful in delineating tumour extent, vascularity and direct invasion into adjacent organs.

Abdominal Neoplasms↗
PubMed2003

Acute pancreatitis associated with biliary disease in children.

BACKGROUND AND AIMS: Biliary disease is one of the most common causes of acute pancreatitis in adults; however, this cause and outcome in children have rarely been described in the literature. Therefore, the present study was conducted to evaluate the role of biliary disease as a cause of acute pancreatitis in children. METHODS: The present study included 56 children with acute pancreatitis, of which 16 (29%) cases were associated with biliary disease. The 16 cases consisted of four boys and 12 girls ranging in age from 2 to 13 years. The underlying causes of the biliary disease were evaluated, as well as its clinical presentations, management modalities, and outcomes. RESULTS: The causes of biliary disease in the 16 children included choledochal cyst in seven, biliary sludge in six, gallstone in two, and anomalous pancreaticobiliary junction in one. Acute pancreatitis with biliary disease showed increased presentation of jaundice and abnormalities in a liver-function test. Therapeutic interventions were performed more frequently in acute pancreatitis associated with biliary disease. All seven children with choledochal cysts needed hepaticojejunostomy. Of eight children with biliary sludge or gallstones, five children remained free of and two suffered from repeated attacks of pancreatitis after endoscopic papillotomy. Mortality did not occur. CONCLUSION: The present study suggests that biliary disease can be one of the causes of acute pancreatitis in children and has the clinical characteristics of jaundice and/or abnormalities in a liver-function test. Appropriate therapeutic interventions should be considered as the treatment modality.

Acute Disease↗
PubMed2003

Transcatheter arterial embolization of pulmonary sequestration in neonates: long-term follow-up results.

The purposes of this study are to describe experience with the safety and long-term efficacy of transcatheter arterial embolization (TAE) of pulmonary sequestration in neonates and to introduce a new technique of embolization by an umbilical-artery route. TAE was performed in five neonates, via the femoral artery in one and the umbilical artery in four. Complete regression was achieved in four cases and partial regression (>90%) was obtained in one. TAE is a safe and effective alternative therapeutic modality for the treatment of pulmonary sequestration. The umbilical artery represents a preferable route for performing embolization in neonates.

Bronchopulmonary Sequestration↗
PubMed2003

CT of congenital heart disease: normal anatomy and typical pathologic conditions.

Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital heart disease (CHD). Fast multisection spiral CT can be used to obtain isotropic volume data, and high-quality two- and three-dimensional multiplanar reformatted images can be created to accurately and systematically delineate the normal and pathologic morphologic features of the cardiovascular system. CT may be technically challenging and demanding in uncooperative young children. However, it can be used to systematically evaluate the aorta, pulmonary artery, pulmonary vein, cardiac chambers and ventriculoarterial connection, relationship between the upper lobe bronchi and pulmonary arteries, coronary artery, valves, systemic veins (superior vena cava, inferior vena cava, hepatic veins), and visceral situs with a step-by-step approach. This approach may be helpful in understanding the anatomy of the cardiovascular system in CHD patients. CT has both advantages and disadvantages in evaluating patients with CHD. Nevertheless, it is useful in this setting, and radiologists who perform CT in young children with CHD should be familiar with the advantages and disadvantages of CT and with the normal anatomy and typical pathologic conditions in affected patients.

Aortography↗
PubMed2003

Value of supranormal function and renogram patterns on 99mTc-mercaptoacetyltriglycine scintigraphy in relation to the extent of hydronephrosis for predicting ureteropelvic junction obstruction in the newborn.

UNLABELLED: We investigated the value of supranormal function and renogram patterns on (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) scintigraphy in relation to the extent of hydronephrosis for predicting ureteropelvic junction (UPJ) obstruction in the newborn. METHODS: We studied 48 patients with prenatally diagnosed unilateral hydronephrosis that was confirmed on postnatal ultrasonography. The anteroposterior pelvic diameter (APPD) and the Society for Fetal Urology (SFU) grade were measured on 1-mo ultrasonography to assess the extent of hydronephrosis. Neonates with an APPD of or=55%) and renogram grades (1, not obstructive; 2, indeterminate; 3, obstructive; and 4, prolonged parenchymal transit) were determined on 1-mo (99m)Tc-MAG3 renography. Multivariate logistic regression analysis was performed to predict the presence of obstruction. RESULTS: Of the 48 kidneys with hydronephrosis, 19 were diagnosed as having UPJ obstruction. Twenty-nine kidneys were classified as having nonobstructive hydronephrosis. The APPD of the 19 kidneys with obstruction (24.3 +/- 9.2 mm) was significantly larger than that of the 29 kidneys without obstruction (17.5 +/- 11.2 mm; P < 0.05). The SFU grades of UPJ obstruction (2 with grade 3, 17 with grade 4) were also significantly higher than those without UPJ obstruction (grades 1-4 in 1, 6, 10, and 12 kidneys, respectively; P < 0.01). Supranormal function was present in 4 kidneys with UPJ obstruction but in none without obstruction (P < 0.001). (99m)Tc-MAG3 renography of the 19 obstructions showed grades 2, 3, and 4 renograms in 4, 8, and 7 patients, respectively. The 29 without obstruction revealed significantly lower grades (grades 1-4 in 10, 13, 5, and 1 patient, respectively; P < 0.001). Multivariate logistic regression analysis revealed that the addition of supranormal function or renogram grade in the model significantly increased the likelihood ratio in comparison with that of the SFU grade only (chi(2) = 7.73 and 9.99, respectively; P < 0.01). Of the 29 neonates with SFU grade 4, supranormal function or renogram >or= grade 4 had a positive predictive value of 90% (9/10). CONCLUSION: (99m)Tc-MAG3 renography at 1 mo after birth has a significant additive value in relation to the degree of hydronephrosis in predicting UPJ obstruction in patients with prenatally diagnosed unilateral hydronephrosis with normal function.

False Positive Reactions↗
PubMed2002

Horseshoe lung: useful angiographic and bronchographic images using multidetector-row spiral CT in two infants.

Horseshoe lung is a rare congenital pulmonary anomaly of childhood that can be accompanied with other anomalies. The diagnosis has historically been accomplished with invasive catheter angiography and bronchography rather than CT. Two infants with horseshoe lung were recently diagnosed with CT. We report the imaging findings in these two patients with emphasis on angiographic and bronchographic demonstration of key abnormalities of horseshoe lung using multidetector-row spiral CT.

Angiography↗
PubMed2002

Lateral decubitus HRCT: a simple technique to replace expiratory CT in children with air trapping.

OBJECTIVE: To evaluate the effectiveness of lateral decubitus high-resolution CT (HRCT) in detecting air trapping in children. MATERIALS AND METHODS: HRCT scans of 21 children with heterogeneous lung attenuation caused by air trapping (n = 10) or with infiltrative lung disease (n = 11) were reviewed retrospectively. The air-trapping disease included bronchiolitis obliterans (n = 7), bronchial obstruction due to mediastinal lymphoma (n = 1), endobronchial haemangioma (n = 1) and foreign body aspiration (n = 1). HRCT was performed in both lateral decubitus positions as well as the supine position. The attenuation (Hounsfield units; HU) was measured in both the hypo- and adjacent hyper-attenuating areas of the heterogeneous lung portion, and the difference of attenuation between these two areas was calculated in the supine and both lateral decubitus scans, respectively. The attenuation differences of the three scans were compared in each group. RESULTS: The attenuation difference was larger in the ipsilateral decubitus (207.95 +/- 105.24 HU) scans than in the contralateral (121.25 +/- 90.05 HU) or supine (162 +/- 94.01 HU) scans in the air-trapping group (P < 0.05). There were no significant differences among the three scans in the infiltrative lung disease group (P > 0.05). CONCLUSIONS: Lateral decubitus HRCT is an effective adjunct to standard HRCT in the evaluation of air trapping as a cause of mosaic lung attenuation in uncooperative paediatric patients.

Airway Obstruction↗
PubMedDate not supplied

Acute necrotizing encephalopathy: diffusion MR imaging and localized proton MR spectroscopic findings in two infants.

In this report, we describe the findings of diffusion MR imaging and proton MR spectroscopy in two infants with acute necrotizing encephalopathy in which there was characteristic symmetrical involvement of the thalami. Diffusion MR images of the lesions showed that the observed apparent diffusion coefficient (ADC) decrease was more prominent in the first patient, who had more severe brain damage and a poorer clinical outcome, than in the second. Proton MR spectroscopy detected an increase in the glutamate/glutamine complex and mobile lipids in the first case but only a small increase of lactate in the second. Diffusion MR imaging and proton MR spectroscopy may provide useful information not only for diagnosis but also for estimating the severity and clinical outcome of acute necrotizing encephalopathy.

Brain↗
PubMedDate not supplied

Multi-slice spiral CT of living-related liver transplantation in children: pictorial essay.

In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three-dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection.

Child↗